81 ZXT

Well, I bit the bullet and bought the new alternator NAPA had ordered. (50 bucks - not bad) Installed it last night and solved all my problems. I get 14.5V at the battery and the light doesn't "slightly" glow anymore. I think it may run a little smoother also. I'll know about that when I check the gas milage. Thanks for the advice during this.

Ok, I cleaned every connection that I thought might be involved and then checked my voltage at the battery with the car off. It read 12V. I then started the car and checked at the battery and got 12V. I left the car running and checked the alternator at the back where the connections are and only had 12V. Is there anything that would reduce the reading at the back of the alternator other than a bad alternator (ie broken wire, bad connection, etc)? I really don't think the alternator is putting out anything I am just reading the 12V from my charged up battery.

Thanks for the response. I will go home today and start checking things with my meter. I will let you know what I find.

OK, It's been two years since I first posted the alternator light question. The other day, my battery died and so did car. I charged the battery on my "smart" charger and tested the alternator. It does'nt give voltage readings but said the output was out of normal limts. I took the alternator off and had my local NAPA check it. It was putting out 14.9V but the test concluded with: Alt: BAD. They had ordered a new alternator and tested it. It tested at 15.3V but also concluded with Alt: BAD Is my alternator bad or do I have a wiring problem. I installed the old alternator back yesterday and cleaned all the connections including the battery connections. Again, my smart charger said the alternator was out of normal limits. During all of this the alternator light may have glowed slightly but never actually came on.

I bought a re-built rack and pinion for my 81 turbo for about $290. or $300. The way you can tell that it needs to be replaced is that it leaks into the boot. If you let it go longer the steering will get rather "wiggly". There is step by step instructions on replacing on the website Xenons130.com. It's not too bad of a job but you do have to undo the motor mounts and lift the engine a bit.

Still having this problem. Looked on some other sites and 2 different guys said their AAC was bad. They said they replaced the AAC and that cured the stumbling problem. Looked thru the FSM and could not locate an AAC. Does anyone have any ideas?

I think you are right. I will start at the beginning (always a good place to start) and go thru all of the checks in the service manual. Something has to be out of whack.

OK, so I posted my first plea for help about 2 1/2 weeks ago. Now I realize that I am not an expert, but I see a lot of "non-experts" posting here and getting responses. With the exhaust gas sensor plugged in, I'm getting 17.73 mpg. With it unplugged, I get 15.88 but I have a miss at idle and it is very sluggish when cold. When I first start it up it idles OK but will not take any throttle without backfiring thru the intake and kind of stalling like it is starving for fuel. I am thinking that maybe my head temp sensor could be bad. If it does not realize that the head is heating up, it is simply controlling the injection pulse from readings supplied by the cooling temp sensor and the O2 sensor? I know there are a lot of other factors involved but does anyone have any ideas on what to look for?

OK, so I unplugged the exhaust gas sensor and even though it runs rich, the missing is gone. So with the sensor working, I'm running lean. Could there be another sensor that is bad causing a conflict with the exhaust gas sensor?

81 Turbo - I bought 2 years ago. Fixed a lot of problems but have always thought it was running rich. Changed the exhaust gas (O2) sensor. Now it seems to run leaner (better gas milage and less unburnt gas smell) but it misses at idle. The idle speed has not changed (800 rpm) but there is a miss. Seems to run OK down the road-checked the plugs yesterday and they looked good. Is there anything I should look for? I have already checked: Plug wires - good Plugs - good Dist cap/rotor - good Timing - Spot on Coil - replaced just before o2 sensor Any ideas??

Thanks Stephen, I could not think of a reason the turbo model would need a higher amp alternator, but I had read on a different thread that it was 70 amp. Thanks again for clearing that up.

When I drive my car with the headlights on, the alternator light glows very dimly. I have not had any problems starting and this has been going on for months. I have checked the voltage at the battery with car running and I get about 13.4 or so. Belt is tight, connections cleaned. Is my alternator going bad and if it is, do I have a 60 amp or a 70 amp alternator?

On my thermostat housing I have 2 "plugs" One is the water temperature sensor and the other I thought was the thermotime switch. Now I don't know what it is. It has a hex head and 2 wires going into it. It looks like you have to unscrew the head to get to the wires (not a quick connect plug like an injector). I'll download the turbo section and do some studying. This thread is in the ZX section.

Thanks guys, the pcv valve is working. I will check the head temp sensor and clean the connections to the ecu. I have cleaned several connections under the hood. I will assume I need to disconnect the battery before unplugging the ecu. I have a thermotime sensor, but no cold start valve. What does the thermotime switch do on a turbo car?

Thank you S30Driver. I thought I was stupid or blind. What might cause a flooded condition? You know coughing sputtering and lots of black smoke from the exhaust.

I looked yesterday for my cold start valve and could not find it. According to the book I was using I thought it would be just forward of the air regulator. If I am correct in assuming that all models have a cold start valve, where should mine be? 1981 280zx Turbo.

With the A/C off the car runs great. With it on it accelerates just fine til I get to 3200 rpm and then it stumbles terribly. If I get to around 3800 rpm and then turn on the A/C it stumbles just a little but barely noticable and will maintain pretty well at 3900 +. It started doing this last week. Ran OK with A/C on before. I could notice a difference in power with A/C on but it did not stumble. I changed the fuel filter (it was time anyway) and checked/re-gapped plugs. They looked fairly normal with maybe just a slightly lean condition. Some looked like they were burning/sparking on only one side of the plug. The way it acts to me is that is is electrical not fuel related. By that I mean when I am running at 3400 rpm and flip the A/C on, its like throwing a kill switch on and off. This is on a 1981 280ZX Turbo with A/T. Any suggestions will be appreciated.

Having read this thread and having a problem with my speedometer off about 10%, (speedo shows 10% too slow) is it possible that my cable could be in a bind, causing the 10% difference? I did have a problem with a bouncing gauge but fixed it by bending the cable (the short one that comes out of the gauge and screws in right inside the firewall) and lubricating with cable lube. This is in a 1981 Turbo and automatic, 15" wheels, 205/60 tires.

Check your connectors (probably the ones on top of engine) especially the connections with rubber boots. The rubber is most likely either cracked or gone and the rainwater is finding its way into the boot.

I too have a loud fuel pump (1981 ZX Turbo). Mine was loud when I bought the car and since it did not run very good, I bought a new fuel pump. New pump is just as loud as the old one. Turned out that the problem was not fuel pump but other items. I am inclined to think my loud fuel pump may be a result of a blockage in fuel line (damper?). My fuel pressure is good but I don't know about the volume. That is my next project with this car. I think the loudness is caused by the pump working very hard to pump fuel thru the blockage. Or it could be your pump is dying.

1981 ZX, it has the warning/check display in the center of the dash. When I first start the car I get the green "OK" but after a second or two the display shows the red warning. If I hit the check button, it displays either "tail" or "stop" as in lights. Both the tail lights and brake lights and blinkers work just fine but I still get the warning. Does anyone know what might cause this?

Well Stephen you were right again. Installed the new springs last night and it raised the back end by about 3 inches (looks good). Also stiffened the ride back there. I didn't realize how spongy it was until it wasn't anymore.

My 81 ZX sits too low in the rear. I installed new front struts and rear shocks. The front end lifted nicely but the back is too low. When you are looking at it there is no gap between the wheel well and the tire. Could my springs be worn out and if so where to buy? Car has 158K miles and I just dont think the coil springs could be worn out but that is the only thing that holds the body off of the rear axle. Any suggestions?

Figured it out. There is a heat sheild between the C. converter and the driveshaft. One of the weights on the driveshaft was hitting the guard. When I tightened the guard it only moved it closer to the driveshaft. Some creative bending and no more noise.

Not catalytic converter. The noise has gotten now to the point that it does it at lower speeds. Makes it a little easier to diagnose. I believe it is drivetrain related. At low speeds (less than 20 mph) it sounds like a guard hitting the u-joint of the driveshaft and is worse while turning right. Still only makes noise on decel. It might make some noise while accelerating but is worse when decelerating. I was going to look at it last night but we had storms on Wednesday and I had to clean up some downed trees and such. Maybe tonight.